The rare but fatal consequences of Australian bat lyssavirus (ABLV) infection means guidelines recommending that all exposures be notified, and describing post-exposure prophylaxis remain appropriate, according to an article published in the Medical Journal of Australia.
ABLV is related to rabies and occurs in all four Australian flying fox species. Although transmitted to humans only rarely – usually via bites or scratches – when it is, and when it goes untreated before its active phase, the result is inevitably fatal.
ABLV can present weeks and even years after exposure, is difficult to diagnose and, although treatment regimens exist, “none have proven consistently effective”.
Authors, led by Dr Joshua Francis, a paediatric infectious diseases specialist at Royal Darwin Hospital in the Northern Territory, reviewed the guidelines published by the Communicable Diseases Network of Australia (CDNA) and the US Centers for Disease Control and Prevention. “ABLV infection can be prevented by administration of a post-exposure prophylaxis (PEP) regimen of human rabies immunoglobulin and rabies vaccine”, they wrote.
“[The CDNA guidelines] recommend PEP for contacts who have had exposure to the saliva or neural tissue of an infected person across mucous membranes or broken skin.”
Public and clinician awareness of the dangers of even the smallest contact with bats remained problematic, the authors wrote. Although public awareness and therefore notifications spike after a publicised case, they then fall to baseline after a period of time.
“PEP should be offered to any person who has any history (no matter how long ago) of a bite, scratch or mucous membrane or broken skin contact with the saliva or neural tissue of a potentially infected animal, including any bat in Australia or overseas.
“The expectation that ABLV will continue to be universally fatal in humans warrants a cautious approach, including the administration of PEP when clinically significant contact with infected material occurs”, the authors wrote.
“Health care workers and the Australian public should be well informed of the risk of transmission … in Australia, and educated about the importance and reliability of PEP in preventing disease. “CDNA guidelines for managing potential lyssavirus exposures remain appropriate in the Australian setting.”
Australian bat lyssavirus: implications for public health, Joshua R Francis BAppSc(MedSc), MB BS, FRACP, et al., Medical Journal of Australia, doi: 10.5694/mja13.00261, published 15 December 2014.
Source: Australian Medical Association (AMA)